Construction of multi-story concrete buildings involves sequential floor by floor casting of concrete structures. In order to cast building components such as floor slabs, columns and other features, a casting structure referred to as formwork is used to progressively advance the building upwardly, floor by floor.
This generally involves using a lower floor slab as a support platform for formwork to cast the next floor slab above. In order to support an upper floor slab, upwardly extending building features such as columns and internal walls are also cast to support the upper floor slab once the formwork is removed.
Formwork to create a floor slab will comprise horizontal elements that are positioned between vertical building features such as columns and walls that extend between floor slabs. Reinforced concrete uses reinforcing steel in the form of steel rods, steel frames and mesh, which is positioned on and within formwork prior to pouring of concrete. In the case of vertical building features, the reinforcing framework must extend above and clear of the concrete, so that it is in turn, exposed to allow attachment of further upwardly extending reinforcement formwork. This allows extension of reinforcement frames for the progressive casting of vertical features such as columns or walls.
Only once the lower floor slab is formed, can the formwork for the vertical feature be put in place around the reinforcing steel frame work, ready for casting of the vertical feature above the new floor level.
This causes a delay in setting up the formwork required for the next floor slab. It is necessary for the concrete within the columns or other vertical features to set prior to removal of the formwork, which then enables the formwork for the next floor slab to be put in place. Obviously, the formwork for the next floor slab needs to abut against the vertical features so as to incorporate them in the upwardly extending building structure.
Current column or wall formwork cannot be used concurrently with formwork for creating the next floor slab, as the formwork around the vertical feature could not be removed. Obviously, it will need to extend from the floor surface of the lower slab to the underside surface of the upper floor slab and therefore would be wedged in place between these two concrete surfaces. The formwork would need to be destroyed or broken to be removed.
It is against this background and the problems and difficulties associated therewith that the present invention has been developed.
Certain objects and advantages of the present invention will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.